What does code P2478 mean?

Q: What does code P2478 mean?

Exhaust Gas Temperature Out of Range Bank 1 Sensor 1. P2478 means the engine control module has detected that the exhaust gas temperature reported by bank 1 sensor 1 has moved outside the range the manufacturer considers physically possible for the current operating conditions. The sensor is the first temperature probe in the exhaust stream on the bank that contains cylinder number one, and the computer is flagging a signal that is too high, too low, or changing faster than real exhaust gas can change.

DTC codes / P24xx · Auxiliary emission controls / P2478

P2478Exhaust Gas Temperature Out of Range Bank 1 Sensor 1

P2478 means the engine control module has detected that the exhaust gas temperature reported by bank 1 sensor 1 has moved outside the range the manufacturer considers physically possible for the current operating conditions. The sensor is the first temperature probe in the exhaust stream on the bank that contains cylinder number one, and the computer is flagging a signal that is too high, too low, or changing faster than real exhaust gas can change.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaAuxiliary emission controls

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.